Hair Follicle Aging Is Driven by Transepidermal Elimination of Stem Cells via COL17A1 Proteolysis

The study from February 5, 2016, investigated the role of COL17A1 proteolysis in hair follicle aging and found that the depletion of COL17A1, a protein essential for hair follicle stem cell (HFSC) maintenance, leads to HFSC aging and hair loss. DNA damage response in HFSCs triggers the proteolysis of COL17A1, resulting in the loss of stem cell characteristics and hair follicle miniaturization. The study used mouse models, including transgenic mice with human COL17A1 and mice with conditional knockout of the Col17al gene, to demonstrate that maintaining COL17A1 levels in HFSCs can prevent their depletion and the associated hair follicle aging. Quantitative analyses were performed on groups of 3 mice each, and the results were statistically significant. The findings suggest that interventions targeting COL17A1 maintenance in HFSCs could potentially prevent or reverse hair follicle aging and hair loss.